Indicator for fluid variables



Patented Jan. 26, 1937 PATENT OFFICE 2,068,663 INDICATOR FOR FLUID VARIABLES John C. Diehl, Erie,'Pa., assigner to American Meter Company, New York, N.. Y., a corporation of Delaware Application January 3,

3 Claims.

It is often desirable to indicate a number of variables in fluids in order that these variables may be considered with relation to the fluid. As exemplified the present invention is designed to Aindicate the pressure and temperature of a fluid, such as gas, so that the measurement of that fluid may be more accurately determined. In carrying out the invention I have provided a means whereby a plurality of variables, as for instance, pressure and temperature may be manfest with a single indicator, or recorder, so that a single reading will indicate the modiiications ln the conditions of the fluid which conditions are of importance in computing the flow. Thus the pressure, of course, varies the actual quantity of gas for each foot and in like manner, temperature also varies the quantity of gas in each measuring foot and the present invention establishes a factor which may'be used in determining the actual ilow in standard units. Features and details of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing wherein the structure is shown in a single elevation, partly in section.

I marks a uid conduit, as for instance, a gas line. A pressure tube 2 `is carried from this line and connected with a Bourdon tube, or pressure spring 3, the pressure spring being mounted on a xed support 4. A well 5 is also arranged in the line and a bulb 6 is placed in this well and connected by a tube 'I with 'a Bourdon tube, or spring 8, responding to the pressures induced by the changes in temperature. The tube 8 has its fixed end mounted in a stationary fitting 9.

A pen I0 is carried by a lever, or arm II. This lever is pivotally mounted at I2 on a stationary bracket I3. A link I4 is connected by a pin I5 with the lever II and by a pin I6 with a lever I1. This is pivoted on a pin I8, on a bracket I 9. The lever II is pivotally connected by a link 20 with the free end of the tube 3 and consequently is moved'by the tube in response to changes in pressure. As the pressure in the tube 3 increases in accordance with the pressure in the conduit, the free end moves to the left, or counter-clockwise with an increase of pressure and toward the right, or clock-wise with a decrease of pressure and this movement is conveyed through the lever l1, link I4 to the lever ll/ ,and/many to the pen I 0.

This movement in response to pressure is modifled, however, by variations in temperature. A 55 link 2| is secured by an arm to the free end of i931, Serial No. 506,397

(CCH. 'Z3- 311) the tube 8 and by a pin 22 with the link i4. The pin I 5 is secured in a slot 23 in the lever II so that as the link I4 is moved in response to the movement of the tube B it moves the pin i5 along the slot 23y and consequently Varies the 5 effective lever arm actuated by the link I4. The pin I5 operating in the slot 23 forms a pivotal and sliding connection between the link I4 and the lever II. Thus if the temperature increases the free end of the Bourdon tube 8 moves clockwise and thus moves the pivot I5 through the link I4 away from the pivot I2 so that the change vof the gas through increase of temperature is indicated at the pen and modies the position of the pen in response to pressure in the conduit i acting on the tube 3.

In order to make the initial adjustments the various arms and levers are adjustable. Thus a screw 24 is provided for adjusting the length of the link 20 and a screw 25 for adjusting the connection between the link 20 and the `lever I'I toward and from the pivot I8, a screw 26 for adjusting the length of the link 2I anda screw 21 for adjusting the position of the pin 22 on the linky I4. `By means of these screws the initial adjustment of the apparatus may be accomplished and any variations in the throw of the Bourdon tubes on the linkage leading from the tubes may be varied and a respective response therefrom may be rectied. The link 20 is made in twoparts, the screw 24 being anchored on one part and operating on the other part of the link. The part 20a is provided with a slot 2Gb, and a screw 20c extends through the complementary part of the link and locks the adjustment made by the screw 24. Similarly the link 2I is provided with two members, one part 2Ia having a slot 2lb through which the screw 2| c extends into the complementary member so as to clamp the two parts in adjusted position.

Preferably the pen I0 records its action on a chart 28.

As examples in which thedevice is used, let us assume that we are solving the expression TVXP TX Pv in which Tv=base temperature, as 500 F. absolute.

T=any temperature affecting tube 8. Pv=base pressure as 15 lbs. absolute.

P.=any pressure aflectingtube 3.

The position of rest of the point I0 on the chart 28 when pressure is 15 pounds absolute and the temperature is 500 F. is arranged at zero.

Let us assume that the pressure in the tube 3 has reached 30 pounds absolute while the temperature in the tube 8 is at 500 F. absolute (40 F.)

Under these conditions the tube 3 expands under the pressure and moves the arm i l through the link I4 outwardly over the chart 28. The magnitude of the movement ci the arm il is proportional to the movement of the Bourdon tube 3, times the length of the arm il (from the pivot point I2 to the pen point I0) divided by the distance from the pivot point l2 to the point I5. The position of rest of the point I under these conditions of pressure and temperature on the chart 28 is marked a2, as

@xg-9:@ 500 i5 The chart is then divided for its full scalo into equal 4increments a with the distance ironi Il to 2 as a basis of measurements Now, let us assume an increase in temperature to 100 F. (600 absolute) with a pressure re-n maining at pounds absolute. With the inm crease in temperature the Bourdon tube 8 expands and moves the link I4 and with it the pin I5 away from the lever pivot I2. The resultant movement of the point I0 is, as stated before, proportional to the movement of the tube 3 times the full length of the arm II divided by the distance between the point I2 and thepoint i5. Now since the point I5 has been moved away from the pivot I2 increasing the distance between I2`and I5, While the distance I2 to I0 re mains constant, the ratio of I2 to I5 as to l2 to I0 is increased and the point I0 moves a correspondingly smaller amount, and is equal to 500 new Now as the temperature is increased to 600 F. absolute, the point I5 is moved downward through the action of the Bourdon tube 8 on `the link I4 so that the distance from I2 to I5 is increased to 6". Then with the same pressure of 30 pounds absolute the point I 0 noves sexen@ 1o l/ n: l! 1 X6 1i soo 15 The arm I I is related to the chart so that with r the lever at the zero position, the slot 23 is substantially `tangent to the arc traversed by the link I4 with the temperature at aero position so that a movement of the link accomplished independently ci? substantial movement ci the link in this position. In other positions of the indicating 'the movement of the lint; corrects the position of the arm with relation to the position of the modifying element 8.

What I claim as new isa-'- l. Measuring apparatus ci' tile character forth comprising a pressure responsive element; an arm angularly movable thereby; a pivotal recruiting; an oscillatable arrn secured to the mounting and including a portion provided with a slot; a link pivoted to the pressure responsive arm; a pin fixed to the iinlt and connecting it with the osciilatable arm through its slot for movement in the latter; a temperature respon sive element; an arno angular-ly movable there by; a second link connecting the temperature responsive element arm with the first named link whereby movement of said temperature re sponsive element will move the first named link set forth comprising a device responsive to one iluid condition; a mechanism responsive to a second fluid condition of the same fluid; an oscillatable arm; a pivotal mounting for said arm; a linkage connecting the mechanism with the arm, said linkage comprising a rigid member ex tending from the arm in a direction at substantially right angles thereto; a variable connes tion between the arm and member; means actuated by the device operating on the rigid member to move it along the arm to vary the connecton between the member and the arm, said device varying said connection independently of substantial adjustment of the arm, said means being adjustable along the member to vary the degree of movement of the arm relatively to the movement of the device.

In a measuring apparatus oi the character set forth comprising a pressure responsive element; an arm angularly movable thereby; an oscillatable arm; a pivotal mounting for the oscillatable arm; a linie pivotecl to the pressure responsive arm and slidingiy and pivotally connected with the oscillatable arm; a temperature responsive element; a member movable angular- 1y with relation to the linlr by the temperature responsive element; and a connection between the member and said link whereby movement of said temperature responsive element will move the said link independently of substantial adjustment of the oscillatory arm.

JOHN C. DIEHL.

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